Electrostatic precipitators are well known in the prior art and as an example U.S. Pat. No. 4,725,289 disclose a rigid-frame type electrostatic precipitator. In the operation of an electrostatic precipitator, a gas laden with entrained particulate material is passed through an electrostatic field and corona discharge established about a discharge electrode disposed between two grounded collecting electrodes. The particles in the gas become electrically charged as they pass through the corona discharge and move to, under the influence of the electrostatic field, and deposit upon the grounded collecting electrodes flanking the discharge electrode.
Typically, each collecting electrode is formed of one or more elongated plates disposed in a row side by side and suspended from the top of the precipitator housing in a vertical plane. A plurality of such collecting electrodes is disposed transversely across the width of the precipitator casing in spaced vertical planes parallel to the direction of the gas flow through the precipitator.
In what is commonly referred to as a rigid-frame electrostatic precipitator, a framework comprised of a plurality of discharge electrode frames is suspended from insulators at the top of the precipitator housing to provide a row of vertically disposed discharge electrodes between adjacent collecting electrodes across the width of the precipitator. A voltage is applied to the discharge electrodes to generate the corona discharge and associated electrostatic field.
An electrostatic precipitator design in which discharge frame pipe passes the grounded collecting electrode support beam in the top of the electrostatic precipitators is previously known. The support beam is normally formed of an I-beam or U-beam. However, due to sparking between structural parts the power input to the electrostatic precipitator has become low. In the prior art the I-beam or U-beam has been provided with local cut-outs to increase the distance between the discharge pipe and the beam. Such cut-outs have been found insufficient in recent high voltage testing and spark-over has occurred despite the cut-outs.